Orthodontic brackets are cemented or pasted onto a patient's teeth. Typically the paste is prepared and applied to the bonding surface of the bracket at the time of use. However, pre-pasted bracket systems have been gaining in popularity. According to such systems, the paste is applied to the bonding surface by the manufacturer, and the prepasted bracket is placed in a special package that permits the bracket, with a predetermined quantity of paste attached, to be removed at the time of use. A number of packaging systems have been proposed which provide varying solutions to the problem of removing the pre-pasted bracket without leaving paste behind on the package. Often the prepasted bracket is set in a recess which is then sealed with a cover.
Where the paste is of a type that is cured by exposure to visible light radiation, the packaging should protect the prepasted bracket from curing prematurely. U.S. Pat. No. 4,978,007 describes a packaged element containing (a) a substrate that transmits less than about 0.5% of actinic radiation and has at least one recess, (b) a cover that transmits less than about 0.5% of actinic radiation and transmits at least part of the visible light spectrum, (c) a structure for maintaining the cover in contact with the substrate such that the cover filters incident radiation entering the recess, and (d) an element located in the recess and having a substance thereon that is curable by exposure to the actinic radiation. Cover materials described in the '007 patent include colored transparent films, opaque to the wavelength of light required to cure the paste, but sufficiently transparent to non-curing wavelengths to permit viewing the bracket through the film.
Known systems for storage of prepasted brackets tend to be elaborate, difficult to make structures. Viewing of the bracket may be aesthetically satisfying but is unnecessary, especially when all of the brackets purchased as a set or group are alike. The present invention provides a packaging material and structure that is easier to manufacture, provides better protection for the pasted bracket prior to use, and makes each bracket easier to remove.